Which layer of the sun is responsible for producing the light shown in the picture above? Radiative zone
Convective zone
Photosphere
Chromosphere

What is thought to have caused the mass extinction at the end of the cretaceous period?

When ash and dust begin to settle on the ground, they eventually become compacted by

Which of the following may one conclude from a map that shows the average ph value of rainfall in the u.s.? acid rain is a more serious problem on the east coast. acid rain falls equivalently across the continental u.s. there are more factories on the west coast. the midwest has fewer forests than the rest of the u.s.